Add remote volume slider to sound settings

1. Add RemoteVolumePreferenceController to control volume through
MediaSessions.
2. Add related preference to skip calling AudioManager.

Bug: 126199571
Test: RunSettingsRoboTests
Change-Id: I9cb85ccf5f49be6d127cb61caf445b2ee7dfb579

AndroidManifest.xml

@@ -100,6 +100,7 @@
     <uses-permission android:name="android.permission.USE_RESERVED_DISK" />
     <uses-permission android:name="android.permission.MANAGE_SCOPED_ACCESS_DIRECTORY_PERMISSIONS" />
     <uses-permission android:name="android.permission.CAMERA" />
+    <uses-permission android:name="android.permission.MEDIA_CONTENT_CONTROL" />
 
     <application android:label="@string/settings_label"
             android:icon="@drawable/ic_launcher_settings"

res/values/strings.xml

@@ -7193,6 +7193,9 @@
     <!-- Sound: Title for the option managing media volume. [CHAR LIMIT=30] -->
     <string name="media_volume_option_title">Media volume</string>
 
+    <!-- Sound: Title for the option managing remote media volume. [CHAR LIMIT=30] -->
+    <string name="remote_media_volume_option_title">Cast volume</string>
+
     <!-- Sound: Title for the option managing call volume. [CHAR LIMIT=30] -->
     <string name="call_volume_option_title">Call volume</string>
 

res/xml/sound_settings.xml

@@ -22,6 +22,15 @@
     settings:keywords="@string/keywords_sounds"
     settings:initialExpandedChildrenCount="9">
 
+    <!-- Remote volume -->
+    <com.android.settings.notification.RemoteVolumeSeekBarPreference
+        android:key="remote_volume"
+        android:icon="@drawable/ic_volume_remote"
+        android:title="@string/remote_media_volume_option_title"
+        android:order="-185"
+        settings:allowDynamicSummaryInSlice="true"
+        settings:controller="com.android.settings.notification.RemoteVolumePreferenceController"/>
+
     <!-- Media volume -->
     <com.android.settings.notification.VolumeSeekBarPreference
         android:key="media_volume"

src/com/android/settings/notification/RemoteVolumePreferenceController.java

@@ -0,0 +1,159 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.notification;
+
+import android.content.Context;
+import android.media.session.MediaController;
+import android.media.session.MediaSession;
+import android.media.session.MediaSessionManager;
+import android.os.Looper;
+import android.text.TextUtils;
+
+import androidx.annotation.VisibleForTesting;
+import androidx.lifecycle.OnLifecycleEvent;
+
+import com.android.settings.R;
+import com.android.settingslib.core.lifecycle.Lifecycle;
+import com.android.settingslib.volume.MediaSessions;
+
+import java.util.List;
+
+public class RemoteVolumePreferenceController extends
+    VolumeSeekBarPreferenceController {
+
+    private static final String KEY_REMOTE_VOLUME = "remote_volume";
+    @VisibleForTesting
+    static final int REMOTE_VOLUME = 100;
+
+    private MediaSessionManager mMediaSessionManager;
+    private MediaSessions mMediaSessions;
+    private MediaSession.Token mActiveToken;
+
+    private MediaSessions.Callbacks mCallbacks = new MediaSessions.Callbacks() {
+        @Override
+        public void onRemoteUpdate(MediaSession.Token token, String name,
+                MediaController.PlaybackInfo pi) {
+            mActiveToken = token;
+            mPreference.setMax(pi.getMaxVolume());
+            mPreference.setVisible(true);
+            setSliderPosition(pi.getCurrentVolume());
+        }
+
+        @Override
+        public void onRemoteRemoved(MediaSession.Token t) {
+            if (mActiveToken == t) {
+                mActiveToken = null;
+                mPreference.setVisible(false);
+            }
+        }
+
+        @Override
+        public void onRemoteVolumeChanged(MediaSession.Token token, int flags) {
+            if (mActiveToken == token) {
+                final MediaController mediaController = new MediaController(mContext, token);
+                final MediaController.PlaybackInfo pi = mediaController.getPlaybackInfo();
+                setSliderPosition(pi.getCurrentVolume());
+            }
+        }
+    };
+
+    public RemoteVolumePreferenceController(Context context) {
+        super(context, KEY_REMOTE_VOLUME);
+        mMediaSessionManager = context.getSystemService(MediaSessionManager.class);
+        mMediaSessions = new MediaSessions(context, Looper.getMainLooper(), mCallbacks);
+    }
+
+    @Override
+    public int getAvailabilityStatus() {
+        final List<MediaController> controllers = mMediaSessionManager.getActiveSessions(null);
+        for (MediaController mediaController : controllers) {
+            final MediaController.PlaybackInfo pi = mediaController.getPlaybackInfo();
+            if (isRemote(pi)) {
+                mActiveToken = mediaController.getSessionToken();
+                return AVAILABLE;
+            }
+        }
+
+        // No active remote media at this point
+        return CONDITIONALLY_UNAVAILABLE;
+    }
+
+    @OnLifecycleEvent(Lifecycle.Event.ON_RESUME)
+    public void onResume() {
+        super.onResume();
+        mMediaSessions.init();
+    }
+
+    @OnLifecycleEvent(Lifecycle.Event.ON_PAUSE)
+    public void onPause() {
+        super.onPause();
+        mMediaSessions.destroy();
+    }
+
+    @Override
+    public int getSliderPosition() {
+        if (mPreference != null) {
+            return mPreference.getProgress();
+        }
+        //TODO(b/126199571): get it from media controller
+        return 0;
+    }
+
+    @Override
+    public boolean setSliderPosition(int position) {
+        if (mPreference != null) {
+            mPreference.setProgress(position);
+        }
+        //TODO(b/126199571): set it through media controller
+        return false;
+    }
+
+    @Override
+    public int getMaxSteps() {
+        if (mPreference != null) {
+            return mPreference.getMax();
+        }
+        //TODO(b/126199571): get it from media controller
+        return 0;
+    }
+
+    @Override
+    public boolean isSliceable() {
+        return TextUtils.equals(getPreferenceKey(), KEY_REMOTE_VOLUME);
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return KEY_REMOTE_VOLUME;
+    }
+
+    @Override
+    public int getAudioStream() {
+        // This can be anything because remote volume controller doesn't rely on it.
+        return REMOTE_VOLUME;
+    }
+
+    @Override
+    public int getMuteIcon() {
+        return R.drawable.ic_volume_remote_mute;
+    }
+
+    public static boolean isRemote(MediaController.PlaybackInfo pi) {
+        return pi != null
+                && pi.getPlaybackType() == MediaController.PlaybackInfo.PLAYBACK_TYPE_REMOTE;
+    }
+}

src/com/android/settings/notification/RemoteVolumeSeekBarPreference.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.notification;
+
+import android.content.Context;
+import android.util.AttributeSet;
+
+/**
+ * A slider preference that controls remote volume, which doesn't go through
+ * {@link android.media.AudioManager}
+ **/
+public class RemoteVolumeSeekBarPreference extends VolumeSeekBarPreference {
+
+    public RemoteVolumeSeekBarPreference(Context context, AttributeSet attrs, int defStyleAttr,
+            int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+    }
+
+    public RemoteVolumeSeekBarPreference(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    public RemoteVolumeSeekBarPreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public RemoteVolumeSeekBarPreference(Context context) {
+        super(context);
+    }
+
+    @Override
+    public void setStream(int stream) {
+        // Do nothing here, volume is not controlled by AudioManager
+    }
+
+    @Override
+    protected void init() {
+        if (mSeekBar == null) return;
+        updateIconView();
+        updateSuppressionText();
+    }
+}

src/com/android/settings/notification/SoundSettings.java

@@ -184,6 +184,7 @@ public class SoundSettings extends DashboardFragment implements OnActivityResult
         volumeControllers.add(use(RingVolumePreferenceController.class));
         volumeControllers.add(use(NotificationVolumePreferenceController.class));
         volumeControllers.add(use(CallVolumePreferenceController.class));
+        volumeControllers.add(use(RemoteVolumePreferenceController.class));
 
         use(MediaOutputPreferenceController.class).setCallback(listPreference ->
                 onPreferenceDataChanged(listPreference));

src/com/android/settings/notification/VolumeSeekBarPreference.java

@@ -40,8 +40,8 @@ import java.util.Objects;
 public class VolumeSeekBarPreference extends SeekBarPreference {
     private static final String TAG = "VolumeSeekBarPreference";
 
+    protected SeekBar mSeekBar;
     private int mStream;
-    private SeekBar mSeekBar;
     private SeekBarVolumizer mVolumizer;
     private Callback mCallback;
     private ImageView mIconView;
@@ -121,7 +121,7 @@ public class VolumeSeekBarPreference extends SeekBarPreference {
         init();
     }
 
-    private void init() {
+    protected void init() {
         if (mSeekBar == null) return;
         final SeekBarVolumizer.Callback sbvc = new SeekBarVolumizer.Callback() {
             @Override
@@ -158,7 +158,7 @@ public class VolumeSeekBarPreference extends SeekBarPreference {
         }
     }
 
-    private void updateIconView() {
+    protected void updateIconView() {
         if (mIconView == null) return;
         if (mIconResId != 0) {
             mIconView.setImageResource(mIconResId);
@@ -195,7 +195,7 @@ public class VolumeSeekBarPreference extends SeekBarPreference {
         updateSuppressionText();
     }
 
-    private void updateSuppressionText() {
+    protected void updateSuppressionText() {
         if (mSuppressionTextView != null && mSeekBar != null) {
             mSuppressionTextView.setText(mSuppressionText);
             final boolean showSuppression = !TextUtils.isEmpty(mSuppressionText);

tests/robotests/src/com/android/settings/notification/RemoteVolumePreferenceControllerTest.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.notification;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.when;
+
+import android.content.Context;
+import android.media.session.MediaController;
+import android.media.session.MediaSessionManager;
+
+import com.android.settings.R;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.RuntimeEnvironment;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@RunWith(RobolectricTestRunner.class)
+public class RemoteVolumePreferenceControllerTest {
+
+    @Mock
+    private MediaSessionManager mMediaSessionManager;
+    @Mock
+    private MediaController mMediaController;
+    private RemoteVolumePreferenceController mController;
+    private Context mContext;
+    private List<MediaController> mActiveSessions;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mContext = spy(RuntimeEnvironment.application);
+        when(mContext.getSystemService(MediaSessionManager.class)).thenReturn(mMediaSessionManager);
+        mActiveSessions = new ArrayList<>();
+        mActiveSessions.add(mMediaController);
+        when(mMediaSessionManager.getActiveSessions(null)).thenReturn(
+                mActiveSessions);
+
+        mController = new RemoteVolumePreferenceController(mContext);
+    }
+
+    @Test
+    public void isAvailable_containRemoteMedia_returnTrue() {
+        when(mMediaController.getPlaybackInfo()).thenReturn(
+                new MediaController.PlaybackInfo(MediaController.PlaybackInfo.PLAYBACK_TYPE_REMOTE,
+                        0, 0, 0, null));
+        assertThat(mController.isAvailable()).isTrue();
+    }
+
+    @Test
+    public void isAvailable_noRemoteMedia_returnFalse() {
+        when(mMediaController.getPlaybackInfo()).thenReturn(
+                new MediaController.PlaybackInfo(MediaController.PlaybackInfo.PLAYBACK_TYPE_LOCAL,
+                        0, 0, 0, null));
+        assertThat(mController.isAvailable()).isFalse();
+    }
+
+    @Test
+    public void getMuteIcon_returnMuteIcon() {
+        assertThat(mController.getMuteIcon()).isEqualTo(R.drawable.ic_volume_remote_mute);
+    }
+
+    @Test
+    public void getAudioStream_returnRemoteVolume() {
+        assertThat(mController.getAudioStream()).isEqualTo(
+                RemoteVolumePreferenceController.REMOTE_VOLUME);
+    }
+}